The reaction of an allylic primary alcohol with a lower alkoxy butadienyl ether to give alpha-beta unsaturated aldehydes is disclosed in U.S. Pat. No. 3,634,309, Thomas, Apr. 4, 1972. This reaction was presumed to involve three stages which occur in a single step: transetherification of the butadienyl ether with the primary allylic alcohol to give a new butadienyl ether, followed by sequential Claisen and Cope rearrangements of this substance to yield ultimately an alpha-beta unsaturated aldehyde. According to prior workers (Thomas, J. Amer. Chem. Soc. 91, 3281 (1969); Cookson and Rogers, Chem. Commun. 281 (1972)), this reaction did not follow the course described above when the butadienyl ether is not substituted by an alkyl group on the carbon alpha to the one bearing the alkoxy group. It was also presumed that when butadienyl ethers having such unsubstituted alpha carbon atoms were employed transetherification and the Claisen rearrangement occurred as described above. However, the major and sometimes exclusive product from this reaction appeared to be derived from the Claisen rearrangement product via an undesired rearrangement and could not be converted into the desired alpha-beta unsaturated aldehyde.